Quick mounting and demountable pressure head



Oct. 19, 1954 I BJCONRAD 2,692,066

QUICK MOUNTING AND DEMOUNTABLE PRESSURE HEAD Filed Aug. 19, 1952 Isms/V702.

J6 s j MAer/A/ B. 0NEAD,

ATTOQNE YS Patented Oct. 19, 1954;

it is desirable tubular memb trap fluid under seals in the apparatus. Thus, the seal ring 3|,

previously described, presents leakage of fluid between the central head 29 and the piston 23, whereas an annular pressure plate 36 is disposed across the outer end 29 of the tubular member to prevent leakage along this end, and also along th'eouterpistonskirt-"25." This pressure plate has a ringgroove 3'! in its lower face containing a seal ring 38 that engages the end face 29 of the tubular member, which is preferably made fiat. The periphery of .the pressure plate 36 is also provided with a seal'ring 39 disposed in a peripheral groove 49 and engaging theinner wall of the outer piston skirt 25.: It is, therefore, apparent that the closing of the valve 35 leading from the central head passage 33 will completely pressure within the -tubular member Ill, since the inner piston seal ring BI tapered cam faces I3, I4 will then urge the slips I5 inwardly to obtain an initial bite or digging in of the teeth I9 in the periphery of the tubular member or casing I0. After such initial biting action has occurred, fluid under pressure may be supplied in the tubular member through the inlet pipe 34 and central passage 33, or the pressure may be present naturally-in the tubular member I0, if it constitutes a well casing disposed in a Such pressure will act on the piston 23 and tend to urge it longitudinally away from T the tubular member Ill. The piston, in turn, will tend to move the housing or cylinder II in the same direction... However, since the slips I5 are digging into the tubular member I9, such move- "ment tendency of the housing or cylinder will cause the coengaging cam faces I3, M to dig the wickers I9 of the slips more firmly into the outer precludes leakage of fluid between the centr'al I head 29 and piston 23, whereas the gasket ring '38 and peripheral ring 39 on'thepressureiplate 36 prevent leakage of fluid alongthe'end faceZfl of the tubular member ID, as well as between the periphery of the pressure. plate 36 and the'inner wall'25a-of, the outer piston skirt25. v

It is to be noted-that the gasket ring 38 on the pressure plate 36 engages the end 20 ofthe tubular member II! at a radius which is substantially less than the radius of the inner wall 25a of the outer piston skirt 25. -Accordingly, the pressure in the tubular member In is acting-overadifferential area of .the pressure plate, tending to force the, latter inwardly against the en'd 29 of the tubular member to maintainthe gasket seal ring As the pressure in the tubular member-increases,

the pressure plate is held. more firmly against the end face-of thetubular member. v I

When the slip segments I5 are disposed intheir full inward position with respect to the outer housing II, as disclosed in Fig.1, the teeth I9 lie on a cylindrical curve which is slightly greater than the external diameter of the tubular member Ill. For this reason, thelentire head assembly can be slipped over the end of thetubular member. until the pressure plate 36 engages the tubular member end face-ML Initially, thereis a slight engagement between the pressure plate and thetubiilar member face, imposedby a pmrality of circumferentially spaced ,helic'alifcompression springs llflengag'ing the jpiston.23l and also seats 42 formed in the pressurefpla't e. ,.Only one of these springs Ali's disclosedin the, drawings, but it is to beiunderstood thatia plurality of circumferentially spaced compression springs are so arranged 'aroundthe' apparatus. At this time, pressure shouldno't be provided in the tubular member I0, since'jthe teeth or wicker s I9 on the slips or gripping members I5 arenotengaging the periphery of the tubular ,inember.

Suitable means maybe provided for providing such initial engagement, whereu'ponfthe pres.- sure within the tubular member, will enhance the gripping action or engagement of I the jslips against the peripheryjotiT he tubular. member. Thus, movement ofjthe'piston 23inwardly1to+ ward the tubular member I and relative .to'jthe outerhousing or cylinder. IIfwillcause. the outer piston skirt 25 to'bear -upon'thej slips I and force them longitudinally in a downward direction with'respectto the housing for cylinder II.[ The surface of the tubular member, thereby precluding movement of the housing or cylinder in the direction in which it is tending-to travel. Several different modes; ofobtaining the initial digging in, or bite, of the wickers I9 in the casing Ill, and the transmission-of the pressure forces between the piston' 23 and the outer cylinder II may be provided. As disclosed inthe drawing, fluid means are available to accomplish these objectives. A fluid inlet passage or port 501 provided inthe cylinder head 2I' communicating with the interior of a valvebody 5I threaded in the head and into snug engagement with a seal ring or gasket 52 p-roVided in-a headgroove 53.

This valve body 5| has an inlet port or passage 54 communicating; with apressure inlet pipe55 extending to a suitable sourceof fluid pressure (not shown). Fluid under pressurecan pass from the inlet pipe fifi through the head inletM into the. region'56 betweenthe cylinder head'ZI and the piston head ZIlbut such fluid, is precluded from flowin in reverse direction. To accomplish this purpose, a check valve isprovidedin the valve. body 5 I This check valve includes, a valve head'S'I havinga stern r58l eirtending therefrom, theheadbeing providediwith a tapered portion 59 adaptedto engage a. tapered seat 60- in the valv'ebody, leakagefbetween thehead and seat being preclu ed by al'suitable seal ring 6] v()rlthe 56 between the cylinder ihfead 2i and theflpiston head, 21 Such fluidi'undr pressure urges-the piston 23 inwardly toward the .end.. 29 of the tubular member, causing the skirt 25 to shift the slips I5 longitudinally ,of the cylinder Hand radially, inward into gripping iienga gement' with the exterior .of the tubulariimember :Whenthis action occurs, thererisa cylinder space orgapfit formed between the'cylinderhead and the piston head thei fluidin thisspacebeing prevented from escaping bythe closing of the checkvalve head 51 against its companion seat 90. The cylinder head 2I is also provided with an exhaust port leading to an exhaust line 66,but this exhaust port isnormall'y closed, as by closing a suitable valve 61 provided theexhaustline Accord? ingly, following the initialgripping of the slips I5 with the tubular member or well casing" I9, the imposition of pressure .within the latter will we l es r r asoni ston, 1 tending zaeeaoee direction; 1 means: subject to the pressure of fluid in the tubular member to urge said housing longi-. tudinally of said gripping member in saidone direction; said means beingengageable with said gripping member; and means for shifting said means in the opposite-longitudinal direction to shift said gripping member in such opposite direction and into engagement with the tubular member.

6. In a head assembly for a tubular member: a gripping member having inner teeth adapted to grip the outer surface of the tubular member; a housing surrounding said gripping member and having a transverse :structure to extend across the'end of the tubular member to close the same; said housing and gripping member having co' engaging. cam surfaces to urge said gripping member inwardly against the outer surface of the tubular member upon relative longitudinal movement of said housing and gripping member in one direction; means'subject to the pressure of fluid in the tubular member to urge-said housing longitudinally of said gripping member in said one direction; said means being engageable with said gripping member; means for shifting said means in the opposite longitudinal direction to shift said gripping member in such oppo sitevdirection and into engagement with the tubu lar member; and a pressure member adapted to sealingly engagethe tubular member and said means which is subject to the pressure of fluid in the tubular member, the point of sealing engagement of said pressure member with the tubular -member being at a lesser radius from the axis of the head assembly than the pointlofsealing engagement of said pressure member with said means whichis subjectto the pressure of fluid in the tubular member. I v

'7. In a head assembly-for a tubular member: a; gripping member having-inner teeth adapted to grip the outer'surface of the tubular member; a housing surrounding said gripping member and having a transverse structure to extend across the end .of the tubular member to close the same; said housing and gripping member inwardly against the outer surface of the tubular member upon relative longitudinal movement of said hous-v ing and gripping member in one direction; a pistonin said housing engageable withsaid gripping member to shiftsaid gripping member in one direction relative to said housing and in-q wardly into grippingiengagement with the tubu lar member; and means for feeding fluid under pressure into said housing for action on said pistong U 8. In. a head assembly; for a tubular member a gripping member having inner teeth adapted to grip the outer surface of the tubular member; a housing surrounding said gripping member and having a transverse structure to extend across the end of the tubular member to close the same; said housing and gripping member having coengaging cam surfaces to urg said gripping member inwardly against the outer surface vofthe tubular memberupon relativelongitudinal movement of said housing and gripping member in one direction; a piston in said housing engageable with said gripping member to shift said gripping member in one direction relative to said housing and inwardlyuinto gripping engagement with the tubular member; means for feeding fluid under pressure into said housing for action on said piston; and means for entrapping said fluid under pressure within said housing between said housingand piston. v

9.Ina head assembly vfor a tubular member: a gripping member havinginner teeth adapted to grip the outer surface of the tubular member; ahousing surrounding said gripping member and having atransverse structure to extend across the end of the tubular member to close the same; said housing and gripping member having coengaging cam surfaces to urge said gripping member, inwardly against the outer surface of the tubular member upon relative longitudinal movement of said housing and gripping member in one direction; a piston insaid housing engageable with said gripping member to shift said gripping member in one direction relative to said housing and inwardly into gripping engagement with the tubular member; means for feeding fluid under pressureinto said housing for action on said piston; means for entrapping said fluid under pressurewithin saidhousing between said housing and piston; and means for bleeding 'suchentrapped fluid from said housing.

10. In a head assembly for a tubular member: a gripping member havinginner teeth adapted to grip the outer surface of the tubular member; a housing surrounding said gripping member and having a transversestructure to extend across the end of the tubularmember to close the same; said housing and gripping member having coengaging cam surfaces to urge said gripping member inwardly against the outerv surface of the tubular member-upon relative longitudinal movement of said housing andi'grippingy member in one direction; a piston in said housing engageable with said gripping member to shift said gripping member in one direction relative to said housing and inwardlyintogripping engagement with the tubular member; means for feeding fluid under pressure into said housing for action on said piston; and a pressure member adapted to sealingly engage said piston-and the tubular member, the point of sealing engagement of said pressure member with the tubular member being at a lesser radius from the axis of the head assembly than the point of sealing engagement of said pressure member with said piston.

11. In a head assembly for a tubular member: av gripping member having inner teeth adapted to grip the outer surface of the tubular member; a housingsurrounding said gripping member and having a .transversestructure to extend across the end of the tubular member to close the same; said housing and gripping member having coengaging cam surfaces to urge said gripping member inwardly against the outer surface of the tubular member upon relative longitudinal movement of said housing and gripping member in one direction; a piston in said housing engageable with said gripping member to shift said gripping: member in one direction relative to said housing and inwardlyinto gripping engagement with the tubular member; means for feeding fluid under pressure into said housing for action on said piston; a pressure member adapted to sealingly engage said piston and the tubular member, the point of sealing engagement of said pressure member with the tubular member being at a lesser radius from the axis of the head assembly than the point of sealing engagement of. said pressure member with said piston; and means for bleeding such entrapped fluid from said housing.

12. In a head assembly for a tubular member: a gripping member having inner teeth adapted to grip the outer surface of the tubular member; a housing surrounding said gripping member and having a transverse structure to extend across the end of the tubular member to close the same; said housing and gripping member having coengaging tapered cam surfaces to urge said gripping member inwardly against the outer surface of the tubular member upon relative longitudinal movement of said housing and gripping member in one direction; said cam surfaces tapering inwardly toward the axis of the head assembly in a direction leading away from said transverse structure; a piston in said housing engageable with said gripping member to shift said gripping member longitudinally of the housing in a direction leading away from said transverse structure and inwardly into gripping engagement with the tubular member; and means for feeding fluid under pressure into said housing for action on said piston.

13. In a head assembly for a tubular member: a gripping member having inner teeth adapted to grip the outer surface of the tubular member; a housing surrounding said gripping member and having a transverse structure to extend across the end of the tubular member to close the same; said housing and gripping member having c0- engaging tapered cam surfaces to urge said gripping member inwardly against the outer surface of the tubular member upon relative longitudinal movement of said housing and gripping member iii in one direction; said cam surfaces tapering inwardly toward the axis of the head assembly in a direction leading away from said transverse structure; a piston in said housing engageable with said gripping member to shift said gripping member longitudinally of the housing in a direction leading away from said transverse structure and inwardly into gripping engagement with the tubular member; means for feeding fluid under pressure into said housing for action on said piston; and a pressure plate engageable with a transverse surface of the tubular member and with said piston; sealing means between said piston and pressure plate; sealing means between said pressure plate and the transverse surface of the tubular member; the radial distance of said piston sealing means from the axis of the head assembly being greater than the radial distance of said tubular member sealing means from such axis.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1, 14, Robinson Oct. 27, 1914 1,323,660 Thrift Dec. 2, 1919 1,5 29 Weiler June, 22, 1926 1,928,833 Grant Oct. 3, 1933 

